Method of protecting furnace brickwork



Patented Sept. 10, 1929.

- UNITED. STATES 'JRAIENT OFFICE.

mm swlrznn KOOBE or EL raso, -'rrnias, assronon. 'ro AMERICAN snnurmearm nnrmme comrm, or NEW YORK, N. Y., "a conrona'rron or NEW mnsnr.

. METHOD OF PROTECTING FURNACE BRIGKTWORK.

llo Drawing.

This invention relates to a method of protecting furnace brick work fromthe erosive action of combustible materials.

It has been found that furnace charges 5 combine chemically withadjacent surfaces such as a brick furnace lining and causedisintegration'thereof. Should a silicious brick lining be employed anda basic charge burned in the furnace, the fine particles of dust setfree by the charge dropping into the furnace coming in contact with thelining will set up a chemical'or fluxing action which results in thewearing awayorerosion of the material. Difiiculty may also beexperienced by reason of the charge being too readily fusible whereby aportion of said dust may become fused upon contact with'the sides androof of the furnace. This fused material is then capable of exerting astronger chemical action upon 0 the exposed surfaces than would be thegase were it maintained in solid form.

This invention provides for the protection of furnace linings by theaddition of a neu tralizing material blown into the furnace as as dustwhen the charge is dropped whereby the dust from the charge comingincontact with said lining will be prevented from reactin chemicallytherewith. The nature an amount of the materialadded will depend uponthe specific type of charge and lining em loyed in each; particularcase.

thou h the novel features which are be lie'ved'to ircliaracteristic ofthis invention will be particularl pointed out in the claims -a pendedhereto, t e invention itself, as to its o ects and advantages, the modeof its operation and-the manner of its organization may be betterunderstood by -'referrmg to the following description in which aarticular commercial embodiment thereof is disclosed. It will beunderstood however, that the procidentified by specific names forconvenience but they are intended to beas generic in their applicationas the art will permit. a

Application filed September a, 1927. -Seria1-1Io. 218,870.

As a specific example, the process in accordance' with the presentinvention may be a plied to a reverberator furnace having a. si iciousbrick linin usual basic charge, e dust particles from the droppin chargecoming in contact with the lining W l exert a chemical or fluxing actionthereon with the consequent erosion or wearing away of the surfaceparticles. It

has been found in practice that the; linin must be renewed after a givennumber -0 charges n order to replace the material which has been lost byreason of .the above mentioned action. In accordance with thepresent'invention a neutralizing material preferably in a finely groundform is blowninto the furnace as dust, preferably at the time ofinserting the charge. therein. This material should be of such naturethat'the chemical action. ordinarily produced by'the charge isneutralized therey. 'For example, a silicious material com.- prisingaluminous clay, mill tailings or other suitable substances hasbeen foundsatisfactory. b

By neutralizin charge of a rever ratory furnace having a l siliciouslining by using an excess of the neuthe dust from the basic n the caseof the,

tralizing material, it has been found that the furnace brick work may bebuilt up and caused to increase in thickness. The quantity ofneutralizing material may, however,

be suitably determined to maintain the thickness of the lining constantand prevent either building up or wearing away thereof. Obviously, thenecessity of renewals will thereby be largely eliminated.

In the case of coal-firing ofreverberatory furnaces or boilers,'the ashhas been found to attack the refractory lining due to the fusibilitythereof. In accordance with the present process, a suitable quantity ofneutralizing material such as silica or alumina may be fed into thefurnace in conjunction with the coal to raise the fusion point of themixture above the temperature of the furnace and preventthe ash fromreacting with the lining or forming slag in the ash pit. It has beenfound'that a coal with a silicious ash may actually build up the liningwhereas it had been rapidly eroded when a coal having a low fusible ashhad been used.

Various means may be employed for injecting a neutralizing material,into the furnace since it may be pre-mixed with the charge in suitableproportions or it may be separately injected at the time of the additionof the charge or at such other times as may be found necessary tomaintain the atmosphere in contact with the lining in neutral condition.

It has been found convenient and satisfactory in reverbcratory furnaceoperation to injuct a quantity of finely powdered silicious dust intothe combustion chamber simultaneously with the usual basic charge. Sucha procedure has been found to produce. the above mentioned desirableresult and to permit a ready control by varying the amount ofneutralization material added and the time 'of addition to suit therequirements of a particular case. The proper proportions may be readilydetermined by observing the surface of the brick work as the combustionprogresses and noting from time to time the condition thereof. It hasbeen found preferable to use an excess of neutralizing material in orderto positively prevent erosion of the lining even though a slightbuilding up is produced therebya The above mentioned process provides acheap and practical means for preventing frequent renewals of furnacelinings and the consequent expense attached thereto. This results in asubstantial saving since, in addition to the cost of lining materialsand labor, the furnace must be removed from operation while beingrepaired thereby increasing the overhead. Y

Although certain. novel features of the invention have been shown anddescribed and are pointed out in the annexed claims, it will beunderstood that various omissions, substitutions and changes in theseveral steps of the process and in its operation may be made by thoseskilled in the art Without departing from the spirit of the invention.

What is claimed is: 1. The method of protecting furnace brick work fromthe erosive action of the-charge burned therein, which comprisesinserting into the furnace a neutralizing material in dust form forpreventing the particles of the charge in contact with the brick workfrom burned therein, which comprises injecting" an acid lining withacharge having a basic reaction, which comprises injecting into saidfurnace an acid dust material in quantities sufiicient to neutralize thedust formed in dropping said charge.

4. The process of feeding a basic charge into a furnace having asilicious lining, which comprises injectin into said furnace avquantityof silicious dust material suflicient to neutralize the d ust'formed bydropping said charge whereby reaction between said charge and saidlining is prevented. 5. The process of feeding a reverberatory furnace,having an acid lining, which comprises injecting a quantity of finelydivided acid material as dust into the presence of a basic chargewhereby chemical reaction'between said lining and dust from said chargeis prevented.

6. The process of feeding a reverberatory furnace having an acid lining,which comprises injecting a quantity of silicious material as dust intothe presence of a basic charge whereby chemical reaction between saidlining and dust arising from said charge is prevented.

7 The process of feeding a reverberatory furnace having an acid lining,which comprises injecting a quantity of silica dust into the presence ofa basic charge whereby chemical reaction between said lining and dustfrom said charge is prevented.

8. The process of feeding a reverberatory furnace having a siliciouslining, which comprises injecting'a quantity of acid material as dustinto the presence of a basic charge whereby chemical reaction betweensaid lining and dust from said charge is prevented.

' 9. The process of operating a combustion chamberhavinga liningsusceptible to'attack I by the ash of the material burned therein, whichcomprises introducing into said com-' bustionchamber as dust in thepresence of a charge a material capableof preventing said ash fromreacting with said lining by raising the fusion point of the mixtureabove the temperature of the furnace.

10. The process of feeding a combustion :chamber having an acid lininwhich comprises introducing into said com ustion chamher a charge havinga basic reaction and neutralizing the dust from said charge with a dusthaving an acid reaction.

11. The process of feeding a combustion chamber having a siliciouslining, which comprises introducing therein a charge having a 7 basicreaction and neutralizing the dust from into said furnace a neutralizingdust, saidv dust'beingcapableof combining with the dust of the furnacecharge and neutralizing any chemical action betweefmsaid dust and saidbrickwork. I 3. The process offeeding a furnace having said charge bythe addition of a silicious dust whereby reaction thereof with saidlining is prevented. I

12. .The process of feeding a combustion chamber having a siliciouslining, which comprises introducing therein acharge having a basicreactionand neutralizing the dust from said charge by the addition of asilica dust whereby reaction thereof with said lining is prevented.

In testimony whereof I have hereunto set my hand.

RALPH SWITZER MOORE.

